# Find n terms of Fibonacci type series with given first two terms

Given first two numbers of series, find **n** terms of series with these two numbers. The given series follows the same concept as Fibonacci series, i.e., n-th term is sum of (n-1)-th and (n-2)-th terms.

Examples:

Input: first = 5, sec = 8, n = 5 Output: 5, 8, 13, 21, 34 Input: first = 2, sec = 4, n = 5 Output: 2, 4, 6, 10, 16

**Approach:**

The approach is similar to finding Fibonacci series where the summation of last two terms form the next term. Find the sum of first two given numbers, second number now will serve as first number to find the next term and the sum produced will serve as second number to find the next term. Sum of these two newly formed first and second term will form the next required term.

Below is the implementation program:

## C++

`// C++ program to find n terms of` `// series from given two numbers` `#include <bits/stdc++.h>` `using` `namespace` `std;` `// Function to find n terms` `// of series` `void` `findSeries(` `int` `num, ` `int` `first, ` `int` `sec)` `{` ` ` `cout << first << ` `" "` `<< sec << ` `" "` `;` ` ` `int` `counter = 0, sum;` ` ` `// find next (num - 2) terms of series` ` ` `// as first two terms are already given` ` ` `while` `(counter < num - 2) {` ` ` `sum = first + sec;` ` ` `cout << sum << ` `" "` `;` ` ` `first = sec;` ` ` `sec = sum;` ` ` `counter++;` ` ` `}` `}` `// Drivers code` `int` `main()` `{` ` ` `int` `n = 5, first = 2, sec = 4;` ` ` `findSeries(n, first, sec);` ` ` `return` `0;` `}` |

## Java

`// Java program to find n terms of` `// series from given two numbers` `import` `java.io.*;` `class` `GFG {` ` ` `// Function to find n terms` ` ` `// of series` ` ` `static` `void` `findSeries(` `int` `num,` ` ` `int` `first, ` `int` `sec)` ` ` `{` ` ` ` ` `System.out.print(first + ` `" "` ` ` `+ sec + ` `" "` `);` ` ` `int` `counter = ` `0` `, sum;` ` ` ` ` `// find next (num - 2) terms` ` ` `// of series as first two` ` ` `// terms are already given` ` ` `while` `(counter < num - ` `2` `)` ` ` `{` ` ` `sum = first + sec;` ` ` `System.out.print( sum + ` `" "` `);` ` ` `first = sec;` ` ` `sec = sum;` ` ` `counter++;` ` ` `}` ` ` `}` ` ` ` ` `// Drivers code` ` ` `public` `static` `void` `main (String[] args)` ` ` `{` ` ` `int` `n = ` `5` `, first = ` `2` `, sec = ` `4` `;` ` ` ` ` `findSeries(n, first, sec);` ` ` `}` `}` `// This code is contributed by vt_m.` |

## Python3

`# Python3 program to find n terms of` `# series from given two numbers` `# Function to find n terms` `# of series` `def` `findSeries(num, first, sec) :` ` ` `print` `(` `"{} {} "` `.` `format` `(first, sec),` ` ` `end` `=` `"")` ` ` `counter ` `=` `0` ` ` `# find next (num - 2) terms of` ` ` `# series as first two terms are` ` ` `# already given` ` ` `while` `(counter < num ` `-` `2` `):` ` ` `sum` `=` `first ` `+` `sec` ` ` `print` `(` `"{} "` `.` `format` `(` `sum` `), end` `=` `"")` ` ` `first ` `=` `sec` ` ` `sec ` `=` `sum` ` ` `counter ` `=` `counter ` `+` `1` `# Drivers code` `n ` `=` `5` `first ` `=` `2` `sec ` `=` `4` `findSeries(n, first, sec)` `# This code is contributed by` `# Manish Shaw (manishshaw1)` |

## C#

`// C# program to find n terms of` `// series from given two numbers` `using` `System;` `class` `GFG {` ` ` `// Function to find n terms` ` ` `// of series` ` ` `static` `void` `findSeries(` `int` `num,` ` ` `int` `first, ` `int` `sec)` ` ` `{` ` ` ` ` `Console.Write(first + ` `" "` ` ` `+ sec + ` `" "` `);` ` ` `int` `counter = 0, sum;` ` ` ` ` `// find next (num - 2) terms` ` ` `// of series as first two` ` ` `// terms are already given` ` ` `while` `(counter < num - 2)` ` ` `{` ` ` `sum = first + sec;` ` ` `Console.Write( sum + ` `" "` `);` ` ` `first = sec;` ` ` `sec = sum;` ` ` `counter++;` ` ` `}` ` ` `}` ` ` ` ` `// Drivers code` ` ` `public` `static` `void` `Main ()` ` ` `{` ` ` `int` `n = 5, first = 2, sec = 4;` ` ` ` ` `findSeries(n, first, sec);` ` ` `}` `}` `// This code is contributed by anuj_67.` |

## PHP

`<?php` `// PHP program to find n terms of` `// series from given two numbers` `// Function to find n terms` `// of series` `function` `findSeries( ` `$num` `, ` `$first` `, ` `$sec` `)` `{` ` ` `echo` `$first` `, ` `" "` `, ` `$sec` `, ` `" "` `;` ` ` `$counter` `= 0; ` `$sum` `;` ` ` `// find next (num - 2) terms of series` ` ` `// as first two terms are already given` ` ` `while` `(` `$counter` `< ` `$num` `- 2)` ` ` `{` ` ` `$sum` `= ` `$first` `+ ` `$sec` `;` ` ` `echo` `$sum` `, ` `" "` `;` ` ` `$first` `= ` `$sec` `;` ` ` `$sec` `= ` `$sum` `;` ` ` `$counter` `++;` ` ` `}` `}` ` ` `// Driver Code` ` ` `$n` `= 5;` ` ` `$first` `= 2;` ` ` `$sec` `= 4;` ` ` `findSeries(` `$n` `, ` `$first` `, ` `$sec` `);` `// This code is contributed by anuj_67.` `?>` |

## Javascript

`<script>` `// javascript program to find n terms of` `// series from given two numbers` `// Function to find n terms` `// of series` `function` `findSeries( num, first, sec)` `{` ` ` `document.write(first + ` `" "` `+ sec + ` `" "` `);` ` ` `let counter = 0, sum;` ` ` `// find next (num - 2) terms of series` ` ` `// as first two terms are already given` ` ` `while` `(counter < num - 2)` ` ` `{` ` ` `sum = first + sec;` ` ` `document.write(sum + ` `" "` `);` ` ` `first = sec;` ` ` `sec = sum;` ` ` `counter++;` ` ` `}` `}` `// Drivers code` ` ` `let n = 5, first = 2, sec = 4;` ` ` `findSeries(n, first, sec);` ` ` `// This code is contributed by Rajput-Ji` `</script>` |

**Output:**

2 4 6 10 16

* Time Complexity: *O(n), where N represents the given integer.

*O(1), no extra space is required, so it is a constant.*

**Auxiliary Space:**Similarly, To find Nth number, generate N terms of series in the above manner and print Nth number.